The present invention relates generally to vehicle fascias and a bracket welded to the interior surface of a vehicle fascia.
In general, vehicle fascias are aesthetic components that vehicle manufacturers use to cover certain functional areas of a vehicle. As shown in FIG. 1, one area where a vehicle fascia may be used is on a vehicle bumper. In the particular example of FIG. 1, the fascia is attached to the front bumper of an automobile. Fascias may also be used on the rear bumper of a vehicle and elsewhere as well. Although a fascia may be considered primarily to be an aesthetic component, various functional components may also be attached to a fascia. For example, in the case of an automobile front bumper, a license plate may be attached to the exterior surface of the fascia, and headlights may be mounted on the fascia.
It may also be desirable to attach various types of brackets to the interior surface of a vehicle fascia. For example in FIG. 1, an impact sensor is shown welded to the interior surface of a front bumper fascia. The impact sensor may be an accelerometer or other type of sensor designed to monitor the front bumper fascia for impact forces that may occur, for example, when the vehicle impacts a pedestrian. And electrical wire connects the impact sensor to a control system in the vehicle in order to transmit impact data to the control system. In the event of an impact with a pedestrian, the control system may activate a pedestrian protection system. For example, the hood of the vehicle may be raised in response to impact data from the sensor. The raised hood is designed to catch the pedestrian's body and may thereafter be designed to drop back down to absorb the energy of the impact in a controlled manner that minimizes injury to the pedestrian.
However, attaching brackets to the interior surface of a vehicle fascia can be difficult and costly. A fascia is generally a plastic component that is molded with a generally constant thin-wall thickness. Although the thickness of a fascia may vary to a certain degree, a plastic material with a thin-wall thickness is generally desired since the fascia is primarily an aesthetic component, and thus, structural strength is not a primary concern. Also, it is desirable to minimize the cost of the fascia. However, because the exterior surface of the fascia is primarily an aesthetic surface, the exterior surface must remain smooth and unblemished. A uniform wall thickness is generally helpful in maintaining the desired smooth, unblemished exterior surface during manufacturing, since the fascia is typically made by a molding process and significant wall thickness changes could make it difficult to reliably mold a smooth exterior aesthetic surface.
As shown in FIG. 1, vehicle fascias are typically curved structures that are molded in an aesthetic shape that is desirable for the particular vehicle it is designed for. Although not illustrated in FIG. 1, a fascia typically has a three-dimensional shape with the curvature of the fascia extending in multiple directions. While the exterior and interior surfaces of all fascias typically have some amount of curvature at least in certain areas, front bumper fascias typically have more curvature in their shape compared to other fascias since the front bumper defines the leading surface of a vehicle, and an aerodynamic exterior surface is usually desired.
Because the interior surface of a vehicle fascia is usually curved, brackets that are attached to the interior surface of a fascia are normally curved to match the curvature of the interior surface of the fascia. A conventional bracket with a matching curved shape may then be welded to the interior surface of a fascia, and various functional components, such as an impact sensor, may be attached to the bracket. However, conventional brackets designed with a matching curvature present a number of problems that the invention described below may overcome. For example, because most vehicle models are designed with different exterior aesthetics, each vehicle model is typically designed with special fascias designed only for that particular vehicle. Thus, each vehicle model typically has its own fascias that are different from all other fascias used on other vehicle models. Thus, in the vehicle industry as a whole, there are many different styles of fascias that are used. As a result, a conventional bracket with a matching curved shape can only be used for the specific fascia it was designed for, and different brackets must be designed for each vehicle model.
In addition, for some brackets an individual vehicle may require multiple sensors and brackets attached to a single fascia. For example, when a vehicle is provided with a pedestrian protection system, the front bumper fascia is typically provided with three to five impact sensors like in FIG. 1 along the length of the fascia. This allows the protection system to monitor impacts at multiple points on the front bumper fascia. However, because a front bumper fascia is typically defined by a complex three-dimensional curved shape, it is not uncommon for each sensor on a single fascia to require a unique curved bracket that is specially shaped for that particular spot where each bracket will be attached to the fascia.
Another problem with conventional brackets with matching curved shapes is that they must be precisely positioned in the exact spot on the fascia that the bracket is designed for. Depending on the shape of the particular fascia involved, correct positioning may require a high degree of precision both in positioning the bracket in the X and Y directions but also rotationally. That is, because the fascia and the matching bracket are designed with a unique, matching shape, a complete match in the curved shapes of the fascia and the bracket may only occur at a specific point where the bracket was designed to be attached. Also, because the curvatures involved may be three-dimensional and different around the periphery of the bracket, precise rotational alignment may also be required.
If a conventional bracket with a matching curved shape is mispositioned or misrotated on the fascia when it is welded to the fascia, the bracket may deform the fascia when it is welded to the interior surface of the fascia. That is, if the curved shapes of the fascia and the bracket do not match due to mispositioning or misrotation of the bracket, the mismatched curved shapes will be squeezed together during welding of the bracket to the fascia. Because the fascia is typically a thin-walled plastic component that is readily deformable, such a mismatch between the bracket and the interior surface of the fascia may cause the fascia wall to deform, and the deformation may be visible on the exterior surface of the fascia. This is undesirable because, as noted, the exterior surface of the fascia is an aesthetic surface that is preferably smooth and unblemished.
Accordingly, the inventors believe that an improved bracket for mounting to the interior surface of a vehicle fascia would be desirable.